The present invention relates generally to refrigerated coolers and more particularly to forced air coolers of type adapted for use in schools as a milk cooler which provides easily access by students to the chilled milk containers stored therein.
Forced air coolers are commonly used in schools to chill milk containers for self-service access. Students passing through the cafeteria line reach in to the cooler through a door opening on one side of the cooler or through either of a pair of door openings provided on opposite sides on the cooler to accommodate two lines of students passing by the cooler. The door/doors when open provide access to the interior of the cooler wherein the milk containers are stored. In conventional forced air coolers, the refrigeration system includes an evaporator/fan system adapted to blow refrigerated air into the uppermost region of the cooler interior across the top of the cooler and collect return air from the bottom region of the cooler.
In U.S. Pat. No. 3,196,632, Buffington discloses a forced air cooler including a cabinet defining a relatively long and relatively low rectangular chamber for chilling containers and having an upper portion of the front wall of the cabinet which is removable to provide access to the chilled product within the chamber. An evaporator and circulating fan are disposed along the back wall of the chamber. Refrigerated air discharges horizontally across the top of the chamber towards the front and the opposite end walls of the chamber and returns, for cooling and recirculation, to a fan inlet which is centrally located at the lower portion of the back wall of the chamber. Thus, the refrigerated air passes outwardly across the top of the chamber, thence downwardly along the front and side walls and back to the fan inlet. In the forced air circulation pattern thus established, the refrigerated air chills the product stacked within the chamber.
In U.S. Pat. No. 4,972,682, Smith et al. disclose a forced air cooler defining a rectangular enclosure having a door in the front wall and top thereof for providing self-service access to individuals, such as for example students passing through a school cafeteria line, to individual service beverage containers, such as milk cartons and the like. A plenum housing an evaporator/fan system is disposed in the uppermost region of the cooler atop the chilled enclosure housing the beverage containers and a condenser/compressor system disposed beneath the floor of and exteriorly of the chilled enclosure. A bottom spacer, typically a wire grid having support legs, is placed atop the floor of the cooler to support the baskets of milk containers off the floor of the cooler such that an air flow gap is provided superadjacent the cooler floor and beneath the milk containers. A wire fence, functioning to space the product away from the front wall, is mounted to the inner surface of the front wall of the cooler by means of brackets and screws. An air return air duct is provided along the back wall of the enclosure with its inlet opening to the lower portion of the enclosure and its outlet to the fan plenum. Refrigerated air discharges horizontally outwardly along the length of the plenum toward the front wall of the enclosure and flows generally downwardly to and down the front wall of the enclosure to the floor thereof, thence along the floor toward the back wall of the enclosure and thence upwardly through the air return duct and to return to the fan plenum.
Although the forced air circulation systems disclosed in Buffington and Smith et al. have proven effective for coolers having self-service access through an access door opening along the upper portion of the front wall and/or top of the cooler, there exists a need for a forced air cooler having access doors opening along both the front and the back of the cooler.
It is an object of the present invention to provide a forced air cooler wherein self-service access is provided along both the front and the back walls of the cooler. It is a further object of the present invention to provide such a forced air cooler having an improved cooling air circulation system.
The forced air cooler of the present invention includes a cabinet having a front wall, a back wall, first and second longitudinally spaced side walls, a floor panel and a top panel cooperatively defining a lower chamber for housing articles to be cooled and an upper chamber disposed superadjacent said lower chamber. A diffuser plate having a plurality of airflow openings passing therethrough extends generally horizontally between said lower chamber and said upper chamber. At least one evaporator for cooling air passing therethrough is disposed within said upper chamber. At least one air circulator is positioned within the upper chamber in operative association with the at least one evaporator for generating a flow of cooling air passing through the evaporators. A bottom airflow passage lies superadjacent the floor of the lower chamber beneath the articles housed within the lower chamber. The bottom airflow passage is in flow communication with the interior of the lower chamber and with at least one air return duct extending from its inlet adjacent the floor of the chamber to its outlet opening to the upper chamber.
A first side air return duct lies along side first side wall and a second side air return duct lies the said second side wall. Each side air return duct has an inlet opening superadjacent the floor of the lower chamber and an outlet opening into the upper chamber. A lower air return passage lies superadjacent the floor of the lower chamber and extends between the side air return ducts beneath the articles housed within the lower chamber. The bottom airflow passage is in flow communication with the interior of the lower chamber and with the inlet of each of the first and second side air return ducts.
This improved air circulation system produces the very efficient cooling airflow. Cooling air is drawn through the evaporators by the air circulator, such as one or more fans, and is cooled as it traverses the evaporators. The cooling air leaving the evaporators is then driven by the fans through the openings provided in the diffuser plate to provide a uniformly distributed flow of cooling air across the surface of the articles disposed within the lower chamber and downwardly into the lower chamber to pass through the stacked. Upon reaching the floor of the lower chamber, the cooling airflow passes along the surface of the floor and is drawn into the lower air return passage. The airflow then passes from the lower air return passage into the side air return ducts that extend vertically along the respective side walls of the cabinet and passes upwardly therethrough to exit through the from the side air return ducts into the upper chamber and be again drawn through the evaporators.
Advantageously, a rack or grate having a relatively open wire framework base section with integral edge fences may be positioned on the floor of the lower chamber for supporting articles to be cooled, such as for example a plurality of milk carton caddies stacked in columns, one atop another, within the lower chamber and above the floor thereof so as to provide an airflow gap between the upper surface of floor and the articles support on the rack.